New Gs 500 restoration project best carbs??

[mfleck]

Hello,

   I once rode a gs500 across the country. Now after a long motorcycle le sabbatical I would like another one. The carburetors were always annoying and with my proficiency fuel injection is not hard to program.  What I am embarking on is nice build nothing crazy. My approach is as follows:


   Find a good bike core running or not.

   Try to see about doing a big bore kit (really want to do this). and deck the head or the block

   having a buddy port the head is not out of the question but probably not worth it

   get a cam reground

   Use microsquirt ($700 for all parts) or a really good carburetor setup The stock carb on my last one sucked.

   Do the Bandit rear shock and inertia valves in the front.

   Throw some adv ish tires on it for gravel roads


   The goal is fun, easy to ride, and hopefully under 2500 dollars. I can afford much more but love projects. I need input. The goal is 35ish torque ad 55 hp. The machine is very well known to me as I did a 1.5 month trip on one in 2011. please advise

[mr72]

Get a Versys 650.

Or get a GS500 and don't try to turn it into something it's not, especially the list of things you have put here. That will cost you more than $2500 and some things are basically not possible.

You can get the hp/torque numbers you are looking for, or very close to them, at the crank, with a stock GS500 with the Mk1 carbs and a good exhaust. Getting 55hp at the wheel will require an engine transplant.

[mfleck]

Oh no, I don't intend to get that much at the wheels. If there is a carburetor combo that would work that's desirable. Really don want to make it something it's not just want a clean running machine. I have owned 7 bikes and the Gs I had was dear to my heart. Even rode it on the Tail of the dragon.

[The Buddha]

I really like the 89-00 carbs. When properly setup they perform very very well. A distant 2nd is the 01-02 US carbs. No weird vacuum etc etc on top.
Cool.
Buddha.

[mfleck]

Is there a part number differentiator? I'm still trying to find a decent gs don't want to pay dealer prices

[mr72]

Just find an '89-00 bike then. It'll come with the correct carbs.

Bone stock it makes ~51 hp at the crank, so just with a top end rebuild and rebuilt carbs you should be there. Get a Delkevic SS exhaust and jet up to 40/125, add one washer to shim the needles, probably get you very close to your 55hp target. Some will tell you that changing the airbox and open air filters etc. will make more power, which may be true in the strictest sense, provided you can get everything dialed in just right. But it will change where the engine makes power and make it much harder to tune, so stick with the stock airbox and maybe a UNI drop in filter and be done with it, IMHO. Most of what you will feel about the difference is that it'll be a lot louder with pods or lunchbox, and that will make you THINK it's faster, but unless you ride it >10K rpm all the time you won't actually see an improvement in power. In fact, the bike probably makes more torque with the stock exhaust with the little "H" pipe.

As for tires, just get whatever 80/20 tire you can find IN THE STOCK SIZES. Believe me, going up a size (like I did!) makes the bike's handling less stable. max 110 front, 140 rear on stock rims. FYI Shinko does not make 705s or 804/805 in the right sizes. So prepare to spend real money on tires if you really want to do this. There are not many choices.

[mfleck]

So I need to find a bike to clean up then ! All this info is amazing.

[The Buddha]

A gs barely makes 40 at the wheel and that's on a good shape low mileage bike. In fact its more like 39 as speced by suzuki.
Pipe and K&N and jetted to the sweet spot barely broke 43 for me.
I'll really really urge you to forget those 55 at the wheel hopes unless you are willing to drop loads of $$$ and are willing to live with a hand grenade.

But ofcourse you're shooting for a dirt monster, you may be able to get by with a low low low gearing bike that would barely break 70 but well, its dirt, you're likely to break your neck even at 70.

And compression and all that BS only gets you low rpm grunt. Not higher hp up top. High torque = compression, higher hp = spin faster. So reduce rotating mass, reduce counter weights, lighter and larger valves but stock compression. TBH, both are pointless in your case. A huge rear sprocket, and as light as you can get the bike by dumping the seat frame etc etc is the cheapest way to go. You can dump 30lb off the bike for less than it will cost you to buy 1 lighter valve. And it will work damn well better.

Cool.
Buddha.

[mfleck]

You folks are right. I would be happy to put put  with jetting and a pipe. There are a few less gs500s for sale out there used to be all over.craigslist. Closer to stock the better! I'll put the tinker on the suspension.

[The Buddha]

Whereabouts are you ? Depending on that facebook/marketplace may be a location to check, as is letgo and offerup.
Cool.
Buddha.

[mfleck]

I am located right next to Killeen Texas.

[The Buddha]

I am located right next to Killeen Texas.

Mwaaa 1000+ miles from the bike I had in mind.
Cool.
Buddha.